1. Field of the Invention
The present invention relates to a heat pump system, and more particularly, to a heat pump system that is capable of adjusting a circulation amount of a refrigerant that circulates the heat pump system by increasing or decreasing the amount of the refrigerant of a liquid receiver according to a driving speed of a compressor.
2. Description of the Related Art
In general, a heat pump is a device that performs cooling or heating function using a refrigeration cycle in which a refrigerant is compressed, condensed, expanded and evaporated. A heat pump includes a compressor, a condenser, an evaporator, an expansion valve, and a 4 way valve. A liquid receiver is installed between the condenser and the expansion valve.
The liquid receiver performs a function of temporarily storing a liquid refrigerant condensed by the condenser and of smoothly supplying the refrigerant to the evaporator even when a cooling load or heating load varies. Korean Patent Publication No. 10-2007-0120214 discloses a liquid receiver.
However, in the conventional liquid receiver, it is difficult to adjust the amount of the refrigerant of the liquid receiver according to a driving speed of the compressor. Thus, a circulation amount of the refrigerant is insufficient when the compressor is rotated at a high speed, and the circulation amount of the refrigerant is excessive when the compressor is rotated at a low speed such that performance of the compressor and the heat pump system is lowered.